On East Grand Terre Island, they still find oil in an area that was heavily-oiled in 2010. Earlier this month, cleanup crews there removed 28,000 pounds of tar mats, a mix of sand and oil.

From BP's perspective, the timing was lousy. Only a day earlier, the company had released a report that found most of the effects of the spill were confined to the spring and summer of 2010.

"The big question is what about the stuff on the bottom of the Gulf?" said David Muth with the National Wildlife Federation. "What about the stuff that's on the bottom of the Barataria Bay? No one's ever going to find it."

On the shoreline, Audubon Louisiana Executive Doug Meffert said the stumps of dead mangrove trees signal more loss to come.

"When the stumps eventually degrade, the roots will degrade and the soil will fall apart," Meffert said.

A National Wildlife Federation study released Monday found dolphins in Barataria Bay continue to struggle.

"They're sick and they're sick with problems, with maladies that are associated with exposure to toxic oil," Muth said.

While Louisiana was losing land long before BP's Macondo Well explosion, critics say the spill added another layer onto the troubled coastline.

BP has not provided a spokesperson to state the company's position either on camera or by telephone, relying instead on company press releases. The company released data from the federal Natural Resources Damage Assessment, suggesting "available data does not indicate the spill caused any signficant long-term population-level impact to species in the Gulf."

That contrasts with a National Wildlife Federation report Monday regarding continued high mortality rates of dolphins in Barataria Bay and declines in the numbers of highly-endangered Kemp's ridley sea turtles.